Drum buffers are:

A) A safety margin separating different projects scheduled to use the same resource.
B) Extra safety that is applied to a project immediately after the use of the constrained resource.
C) A constraint separating different projects that requires a common buffer.
D) Extra safety that is applied to a project immediately before the use of the constrained resource.

Extra safety that is applied to a project immediately before the use of the constrained resource.(D)

Explanation:

Drum buffer can be explained as period of time that is used to safeguard the drum resource from the problems that occur from the drum operation.

The aim of the drum buffer effect is to provide a recheck of the work in order not to deviate from the real aim of the project. The buffer makes up for the process variation, and makes the project stable as it gives extra safety which is applied mmediately before using constrained resource.

answer; planning;